Microswitch with readily removable leaf spring actuating means

ABSTRACT

A push button switch including an actuator made up of an operating leg and a mounting leg in &#39;&#39;&#39;&#39;L&#39;&#39;&#39;&#39; formation, the mounting leg being insertable into a recess in the switch body. The mounting leg is longitudinally slit to define separate spring portions which press snugly against opposed walls in the recess. One of the spring portions is formed into a hook which engages a presented edge on the corresponding wall of the recess to keep the actuator captive, but it can be easily removed by pressing the spring portions toward one another. The presented edge is preferably sharp so as to provide a fulcrum for bodily rocking movement of the actuator. The opposed wall surface is preferably crowned to accommodate the rocking movement and the crown preferably has a flat top opposite the sharp edge so that the actuator is resiliently detented into a central reference condition.

United States Patent 1191 Yoshioka [75] Inventor: Hideoki Yoshloka, Osaka, Japan [73] Assignee: Matsushita Electric Works, Ltd.,

Osaka, Japan [22] Filed: Sept. 25, 1972 [21] Appl. No.: 291,896

[30] Foreign Application Priority Data Sept. 30, 1971 46-89995 Nov. 25, 1971 Japan....

[52] US. Cl. 200/153 T, 200/172 A [51] Int. Cl. H0lh 3/02, H0lh 3/04 [58] Field of Search 200/172 A, 153 T [56] References Cited UNITED STATES PATENTS 4/1956 Lauder et a1 200 153 T x 2,911,509 11/1959 Millerwise........ 3,264,444 8/1966 Krauss et a1. 200/172 A FOREIGN PATENTS OR APPLICATIONS 1,495,802 8/1967 France ZOO/172R Japan 46-110782 45] May 7, 1974 Primary ExaminerRobert K. vSchaefer Assistant Examiner Robert A. Vanderhye Attorney, Agent, or Firm-Wolfe, Hubbard, Leydig, Voit, Osann Ltd.

[5 7 ABSTRACT A push button switch including an actuator made up of an operating leg and a mounting leg in L formation, the mounting leg being insertable into a recess in the switch body. The mounting leg-is longitudinally slit to define separate spring portions which press snugly against opposed walls in the recess. One of the spring portions isformed into a hook which engages a presented edge on the corresponding wall of the recess to keep the actuator captive, but it can be easily removed by pressing the spring portions toward one another. The presented edge is preferably sharp so as to provide a fulcrum for bodily rocking movement-of the actuator. The opposed wall surface is preferably crowned to accommodate the rocking movement'and the crown preferably has a flat top opposite the sharp edge so that the actuator is resiliently detented into a central reference condition.

6 Claims, 14 Drawing Figures PATENTEDIAY H914 3809837 SHEEI 1 0F 5 Fig. (PRIOR ART) sleosla? PATENTEDMAY 7 1974 SHEET E OF 5 Fig. 7A

42 ISEEQKE 1 MICROSWITCH WITH READILY REMOVABLE LEAF SPRING ACTUATING MEANS This invention relates to an improvement in pushbutton switches and, more particularly, to a push button switch adapted to easy mounting of actuator or actuating lever for the push button.

Conventional push button switches of this kind are assembled by first fitting the actuator and then overlapping covers or cases and, therefore, there has been involved a defect that the actuator is complicated to fit or mount to the switch body. Since for example, as shown in FIG. 1, projections 34 of an actuator 33 are fitted in a hole 32 provided through both two-split switch bodies 30 and 31, then the two-split switch bodies 30 and 31 are overlapped to be integral with each other through a rivet 35, it has not been easy to mount and dismount the actuator. I

In this kind of push button switch, the type of required actuator-is different depending on the device'to which the switch is applied and, therefore, there has been a defect that push button switches having many kinds of actuators must be prepared. The present invention has been suggested to solve the above mentioned problems by inserting and mounting the actuator into the push button switch at a later stage of assembling the switch.

Principle object of the present invention is therefore to provide a switch actuator which is easy to mount upon, and to remove from, the switch.

Another object of the present invention is to provide a push button switch in which the actuator can be mounted to either of the projected side of the push button and the other side following it and can be operated from either side.

A further object of the present invention is to provide a push button switch in which the actuator'can be easily mounted and dismounted even after the switch is fitted in a narrow space.

Another object of the present invention is to provide a push button switch in which the actuator remains al ways in a proper push button operating stroke position due to its own spring force.

A further object of the present invention is to provide a push button switch having the actuator staggering little in the vertical and horizontal directions.

The present invention shall be explained in the following with reference to the accompanying drawings, in which: i

FIG. 1 is a perspective view of an exemplary one of conventional push button switches showing the actuator dismounted from the switch body.

FIG. 2 is a similar view of an embodiment of the present invention.

FIG. 3 is a fragmentary sectioned view at the mounting recess of the actuator in the embodiment of FIG. 2.

FIG. 4 is a fragmentary sectioned view at the mounting recess of the actuator in another embodiment of the present invention.

FIGS. 5A, 5B and 5C are explanatory views showing respective operational sequences of the actuator and push button.

FIG. 6 is a sectioned view of another embodiment of the actuator mounting recess.

FIGS. 7A and 7B are characteristics diagrams showing therelation of urging force of the actuator to operational force of the switch given through the actuator.

FIGS. 8 and 9 show respectively another embodiment of the present invention, in which FIG. 8 is a per- I a perspective view'showing an actuator employed in the embodiment of FIG. 10 with the two componential parts disassembled.

The present invention shall be first explained with reference to the most basic embodiment in the following.

mon terminal plate 3 and normally closed terminal plate 4 are electrically connected with each other. 6 is an engaging or mounting recess formed in the upper I surface of the switch case 1 and having opposed walls,

one of which has a retaining edge 7, the other wall being flat as indicated at b. An actuator of L shape is provided made of astrip of spring metal having anelongated operating leg 8 and a mounting leg, at right angles thereto, which is longitudinally slit so as to be formed of two bent potions 9, 10 which are sprung, cantilever-fashion, in opposite directions to bear resil iently against the respective walls of the recess. The portion 10 is preferably centered on the strip while the portion 9 symmetrically straddles the portion 10 (see especially FIG. 2). The second bent spring part 10 is bent, in the present instance, at a smaller angle with respect to the elongated leg 8 than the first bent spring part 9. Said second bent spring part .10 is further bent atits free end to form a hook orlocking means 11. Thus, when the first bent spring part 9 is inserted into the mounting recess 6, the locking means 11 is engaged resiliently to the engaging step 7 and the first bent spring part 9 is pressed against the opposite side of the inner peripheral surface b of the engaging recess 6, so that the actuator leg 8 will be mountedto the switch body A overlying the push button 2. 12 is a roller rotatably fitted to the other free end of the actuator leg 8.

The operation-of the push button switch of this embodiment shall be explained in the following. First of all, the first and second bent springs 9 and 10 as'inserted in the mounting recess 6 will be pressed together against their respective resiliencies. In this mounting recess 6, the first bent spring part 9 resiliently contacts the inner peripheral surface b of the recess hook 11 on second bent springpart 10 resiliently contacts the sharp projecting edge 7. The hook l1 acts to prevent the actuator from being pulled out of the recess 6 and the slope above the projection 7 of the recess acts as a guide for inserting the bent part 10. Now, when the ac- In FIGS. 2 and 3, A is a push button switch body, 2

tuator leg 8 is depressed, the first bent spring part 9 of the operating lever willincline with respect to the inner peripheral surface b while in contact at its free end with the lower part of the surface b and the second bent spring part 10 contacting the projecting edge 7 will give a torque to the actuator 8 in the direction reverse to the push button operating direction. When the actuator is not depressed at the free end, the first bent spring part 9 of the actuator will be urged into contact with the inner peripheral surface b of the recess 6 by resiliency of the second bent spring part 10 so as to give a torque to the actuator 8 in the push button operating direction.

As described above, in this embodiment, the projecting edge 7 is formed in the part opposed to the inner peripheral surface b of the actuator'mounting recess 6 provided in the outer surface of the switch case -1, the first and second bent spring parts 9 and 10 of the actuator 8 are inserted in said recess, the second bent spring part '10 is urged into contact with the sharp edge 7, the firstbent spring part 9 is pressed against the inner peripheral surface b and the hook I l at the free end of'the second bent spring part lis hooked over the edge 7. Thus, by only inserting the bent parts 9 and 10 into the mounting recess 6 and locking the hook ll of the bent part 10 with the edge 7, the actuator can be very simply mounted to the switch case. I

F IGS; 4 and SA- -SC show another embodiment which is, while including all the features of the above described fundamental embodiment, most suitably adapted to practical uses.

This embodiment is somewhat different from the at the lower end of the tapered part 6b, similarly to the above embodiment, the surface of the opposed wall is crowned, being formed of an upward tapered part 6d, flat part 6e and downward tapered part 6f. The edge 6'c of the above mentioned locking step 6c is positioned below a crest line 6'D between the tapered part 6d and flat part 6e but above a crest line 6'fbetween the flat part 6e and tapered part 6f. In short, the flat part is centered opposite the hook-engaging edge to provide a seat defininga reference condition for the actuator.

In FIGS. 5A, B and 5C, there are shown directions of the torque which the actuator 8 will receive from these two bent spring parts 9 and 10 in the respective stages during the operation of depressing the push button.

That is, FIG. 5A shows a state wherein no push button operating force is applied to the actuator leg 8. In such case, the first bent spring part 9 of the actuator will be in resilient contact with the upper crest line 6d of the recess 6'andthesecond bent spring part 10 will be in resilient contact with the edge 6'c of the locking step 6c positioned below the crest line 6'11, and the actuator 8 is receiving a torque in the direction indicated by the arrowF' in the solid-line.

FIG. 5B shows a state wherein a force F for operating the push button is given to the actuator 8 and the push button is depressed substantially to the contact operating position. In such case, the first bent spring part 9 of the actuator will be in resilient contact with the flat part 62 of the recess 6 and the second bent spring; part 10 will be in resilient contact with the edge 6'c of the locking step 6c positioned substantially on the same level as of the flat 6e. As a result, the actuator will receive no torque caused by the resiliencies of the first and second bent spring parts 9 and 10. The condition illustrated in FIG. 5B is thus a detented reference condition.

FIG. 5C shows a state wherein the push button'operating force is further applied .to the actuator leg 8 and the push button is depressed to the end of its operational stroke. In suchcase, the first bent spring part 9 of the actuator will be in resilient contact with the lower crest line 6') and the second bent spring part 10 will be in resilient contact with the edge 6'c of the locking step 6c which is now positioned-abovethe crest line 6'f. As a result, the actuator will receive a reverse torque in the direction indicated by the arrow 'F", that is, in the direction reverse to that of the push button operating force. I

It will be appreciated that such operation can be realized also by making the inner peripheral surface on the side opposed to the push button of the recess 6 to .be a curved surface 6: as shown in FIG. 6, so that its center point will be substantially on the same level as of the edge 6'c of the locking step.

FIGS. 7A and 7B are characteristic diagrams showing the relations between the force received by. the above described actuator 8 from its bentspring parts and .the force of operating the switch through the actuator.

FIG. 7A shows the relations between the operating stroke of the push button and the torque received by 50 shows the case that the actuator is not employed'at all, the chain line 51 shows the case thatan ordinary conventional actuator is employed and the broken line 52 shows the case that the actuatorof the present invention is employed. There is indicated africtional component I: at the hinge part of the ordinary actuator or the like. I

When the actuator of the present invention is thus employed, in case the push button is hard to return due to such reason as catching in theswitch body, at least the. actuator will not act to prevent the push button from being returned. Further, the actuator itself remains always in a proper push button operating stroke position due to the own spring forces and does not stagger in the vertical direction.

FIGS. 8 and 9 show another embodiment of the present invention, wherein the first bent spring part 9 is similarly formed at one end of the actuator, while the second bent spring part 10 is formed at a position spaced by a desired distance from the first bent spring part 9 and is bent in this case substantially at a right angle. The locking means 11 is similarly provided at the free end of the second bent spring part 10. It will be appreciated that when the thus formed actuator is mounted in the recess 6'madeon the upper surface of the switch case, the same will act exactly in the same manner as in the foregoing embodiments. In all of the embodiments described above the actuator is reliably captive, yet the hooked engagement is sufficiently shallow so that the actuator may be easily disengaged simply by squeezing the spring portions 9, together.

FIGS. 10 and 11 show a further embodiment wherein the similar recess 6 having the locking step 7 is made on the upper surface of a switch case 1, a recess 14 having an outernal locking means 13 is made on the side part adjacent to the push button 2, an L-shaped actuator supporting metal fitting 17 having locking means 15 and 16 at both ends is engaged at the both locking means 15 and 16 with the respective recesses 6 and 14, and projections 19 and 19 provided at both side ends of a bent end part of an L-shaped actuator 8 are inserted respectively in hinge parts 18 and 18' provided on the both side parts of the supporting metal fitting 17, so that the actuator 8' will be fitted to the case 1 so as to be rotatable at the other free end. 20 is an aperture through which the push button 2 can project to butt the actuator 8. With such arrangement, the actuator 8' can be mounted to the switch body from the side opposed to that of the case of FIG. 1. The term hook as used herein is a general term to cover any connection providing a hook-type engagement between one of the spring portions of the mounting leg and a cooperating projection on the corresponding wall of the recess.

What I claim is:

1. In a push button switch having a housing and a slid-- ably mounted push button in one side thereof, a spring actuator of L shape having an elongated operating leg overlying the push button and a relatively short mounting leg bent at right angles thereto, the side of the housing having a recess formed therein to receiveamount greater than the spacing of the opposed walls and into snug resilient engagement with the respective opposed walls of the recess so that the actuator is supported with respect to the housing in a reference operating position, one of the spring portions having a hook at its end, and the cooperating wall of the recess presenting a projecting edge engaged by the hook to hold the actuator captive in the recess while nevertheless permitting intentional release by squeezing of the spring portions together adjacent the bend to retract the hook.

2. The combination as claimed in claim 1 in which the actuator is formed of a single strip of spring metal and in which the mounting leg is slit to provide a first spring portion which is in centered position and a second spring portion which symmetrically straddles the first spring portion and which is sprung in the opposite direction.

3. The combination as claimed in claim 1 in which the first and second spring'portions have connection with the actuating leg at bends which are slightly spaced in the longitudinal direction from one another so that the spring portions extendfrom the actuating leg in spaced generally parallel relation.

4. The combination as claimed in claim 1 in which the end of one of the spring portions is formed into a hook and in which the adjacent wall of the recess has a retaining edge engaged by the hook, the opposed wall of the recess which is engaged by the second spring portion being of crowned shape and the retaining edge being relatively sharp so as to enable bodily swing of the actuator about the region of hooked engagement.

to actuation 'of the push button, the remaining spring I portion and its corresponding wall having cooperating seating surfaces in resilient engagement to define a centered reference position for the actuator into which the actuator is constantly biased in the course of its rocking movement, the edge and hook providing such shallow engagement as to permit intentional removal of the actuator simply by pressing the spring portions together. 

1. In a push button switch having a housing and a slidably mounted push button in one side thereof, a spring actuator of ''''L'''' shape having an elongated operating leg overlying the push button and a relatively short mounting leg bent at right angles thereto, the side of the housing having a recess formed therein to receive the end of the mounting leg of the actuator, the recess having a pair of opposed walls, the mounting leg of the actuator being longitudinally slit with the slit extending to the region of the bend to define separate cantilevered spring portions extending from the region of the bend which are sprung away from one another an amount greater than the spacing of the opposed walls and into snug resilient engagement with the respective opposed walls of the recess so that the actuator is supported with respect to the housing in a reference operating position, one of the spring portions having a hook at its end, and the cooperating wall of the recess presenting a projecting edge engaged by the hook to hold the actuator captive in the recess while nevertheless permitting intentional release by squeezing of the spring portions together adjacent the bend to retract the hook.
 2. The combination as claimed in claim 1 in which the actuator is formed of a single strip of spring metal and in which the mounting leg is slit to provide a first spring portion which is in centered position and a second spring portion which symmetrically straddles the first spring portion and which is sprung in the opposite direction.
 3. The combination as claimed in claim 1 in which the first and second spring portions have connection with the actuating leg at bends which are slightly spaced in the longitudinal direction from one another so that the spring portions extend from the actuating leg in spaced generally parallel relation.
 4. The combination as claimed in claim 1 in which the end of one of the spring portions is formed into a hook and in which the adjacent wall of the recess has a retaining edge engaged by the hook, the opposed wall of the recess which is engaged by the second spring portion being of crowned shape and the retaining edge being relatively sharp so as to enable bodily swing of the actuator about the region of hooked engagement.
 5. The combination as claimed in claim 4 in which the crowned wall includes a flat central portion generally centered with respect to the hook and upon which the second spring portion tends to flatly seat to define a detented reference position for the actuator.
 6. The combination as claimed in claim 2 in which the projecting edge is sufficiently well defined, with sufficient adjacent clearance, so that it serves as a fulcrum for bodily rocking movement of the actuator incident to actuation of the push button, the remaining spring portion and its corresponding wall having cooperating seating surfaces in resilient engagement to define a centered reference position for the actuator into which the actuator is constantly biased in the course of its rocking movement, the edge and hook providing such shallow engagement as to permit intentional removal of the actuator simply by pressing the spring portions together. 